Android实现Udp socket通信且对数据进行分包和解析

柔情只为你懂 2021-11-10 09:02 445阅读 0赞

Udp socket通信和Tcp socket通信原理，请参考：  
[《Android中关于Socket通信数据大小，内存缓冲区和数据可靠性的一点调查》][Android_Socket]

### 核心代码 ###

初始化UDP socket和接收Packet：

mUdpSocket = new DatagramSocket(UDP_SOCKET_PORT);
    mRecvPacket = new DatagramPacket(mReceiveByte, PACKAGE_BUFFER_SIZE);

数据发送和分包：

synchronized(mLock) { 
    	InetAddress targetAddress = InetAddress.getByName(UDP_SOCKET_HOST);
    	for( int i = 0; i < packageNum; i++ ){ 
    	    if(i == packageNum - 1 ){ 
    	        mSendBuffer.dataBuf = new byte[(size + 8) - i * PACKAGE_BUFFER_SIZE];
    	        System.arraycopy(buffer, i * PACKAGE_BUFFER_SIZE, mSendBuffer.dataBuf, 0, (size + 8) - i * PACKAGE_BUFFER_SIZE);
    	    }else{ 
    	        mSendBuffer.dataBuf = new byte[PACKAGE_BUFFER_SIZE];
    	        System.arraycopy(buffer, i * PACKAGE_BUFFER_SIZE, mSendBuffer.dataBuf, 0, PACKAGE_BUFFER_SIZE);
    	    }
    	    Log.i(TAG,"sendDataToDashboard,write.size()=" + mSendBuffer.dataBuf.length);
    	    DatagramPacket packet = new DatagramPacket(mSendBuffer.dataBuf, mSendBuffer.dataBuf.length, targetAddress, UDP_SOCKET_PORT);
    	    mUdpSocket.send(packet);
    	}
    }

数据接收和解析：  
readData()

### 完整代码实现： ###

public class AndroidUdpSocketService extends Service { 
        private static final String TAG = AndroidUdpSocketService.class.getName();
        private static DatagramSocket mUdpSocket;
        private static DatagramPacket mRecvPacket;
        private static BackgroundExecutor mBackgroundExecutor;
        private byte[] mReceiveByte = new byte[PACKAGE_BUFFER_SIZE];
        private boolean isAndroidUdpSocketLive = false;
        private static final String UDP_SOCKET_HOST= "255.255.255.255";
        private static final int UDP_SOCKET_PORT= 6002;
        private static final int READ_BUFFER_LENGTH = 1024;
        private static final Object mLock = new Object();
    
        private static final int PACKAGE_BUFFER_SIZE = 50000;
        class SocketDataBuffer
        { 
            byte[] dataBuf;
            int flag;   // 0,middle data; 1,the last data
    
        };
        static SocketDataBuffer mSendBuffer;
    
        @Nullable
        @Override
        public IBinder onBind(Intent intent) { 
            return null;
        }
    
        @Override
        public void onCreate() { 
            super.onCreate();
            Log.i(TAG,"onCreate");
            mBackgroundExecutor = BackgroundExecutor.get();
            mSendBuffer = new SocketDataBuffer();
        }
    
        @Override
        public int onStartCommand(Intent intent, int flags, int startId) { 
            Log.i(TAG,"onStartCommand");
            createNotificationChannel();
            new InitUdpSocketThread().start();
            return super.onStartCommand(intent, flags, startId);
        }
    
        @Override
        public void onDestroy() { 
            super.onDestroy();
            Log.i(TAG,"onDestroy");
            releaseLastSocket();
        }
    
        @Override
        public void onLowMemory() { 
            super.onLowMemory();
            Log.i(TAG,"onLowMemory");
        }
    
        @Override
        public void onTrimMemory(int level) { 
            super.onTrimMemory(level);
            Log.i(TAG,"onTrimMemory");
        }
    
        private void createNotificationChannel() { 
            NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            String id = "car_launcher_02";
            CharSequence name = "AndroidUdpSocketService";
            String description = "Udp Socket Service";
            NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_MIN);
            mChannel.setDescription(description);
            mChannel.setSound(null, null);
            mNotificationManager.createNotificationChannel(mChannel);
            Notification notification = new Notification.Builder(this)
                    .setChannelId(id)
                    .setSmallIcon(R.drawable.ic_home)
                    .build();
            startForeground(12,notification);
        }
    
        class InitUdpSocketThread extends Thread { 
            @Override
            public void run() { 
                super.run();
                try { 
                    Log.i(TAG,"InitSocketThread,new socket");
                    //Start Heartbeat
                    //mHandler.postDelayed(mHeartbeatRunnable, HEART_BEAT_RATE);
    
                    //Create tcp socket connect
                    mUdpSocket = new DatagramSocket(UDP_SOCKET_PORT);
                    mRecvPacket = new DatagramPacket(mReceiveByte, PACKAGE_BUFFER_SIZE);
                    mUdpSocket.setSendBufferSize(1024*1024*10);
                    mUdpSocket.setReceiveBufferSize(1024*1024*10);
    
                    Log.i(TAG,"new Socket,mUdpSocket.getSendBufferSize()=" + mUdpSocket.getSendBufferSize());
                    Log.i(TAG,"new Socket,mUdpSocket.getReceiveBufferSize()=" + mUdpSocket.getReceiveBufferSize());
                    isAndroidUdpSocketLive = true;
                    readDataFromDashboard();
                } catch (IOException e) { 
                    //e.printStackTrace();
                    Log.i(TAG,"new Socket,IOException" + e.getMessage());
                }
            }
        }
    
        private void releaseLastSocket() { 
            isAndroidUdpSocketLive = false;
    
            Log.i(TAG,"releaseLastSocket2");
            if (null != mUdpSocket) { 
                Log.i(TAG,"releaseLastSocket2,mSocket.isClosed()=" + mUdpSocket.isClosed());
                mUdpSocket.close();
                mUdpSocket = null;
            }
        }
    
        public static boolean sendData(final int frameType,final int frameID,final byte[] data) { 
    // Log.i(TAG,"sendData,mUdpSocket != null," + (mUdpSocket != null));
    // Log.i(TAG,"sendData,mUdpSocket.isClosed()," + (mUdpSocket.isClosed()));
    // Log.i(TAG,"sendData,mUdpSocket.isConnected()," + (mUdpSocket.isConnected()));
            if( mUdpSocket != null && !mUdpSocket.isClosed()) { 
                mBackgroundExecutor.submit(new Runnable() { 
                    @Override
                    public void run() { 
                        //do something
                        Log.i(TAG, "sendData,start");
                        int size = data.length;
                        byte buffer[] = new byte[8 + size];
                        buffer[0] = (byte) 0xA6;
                        buffer[1] = 0x6A;
                        buffer[2] = (byte) frameType;
                        buffer[3] = (byte) ((size & 0xff000000) >> 24);
                        buffer[4] = (byte) ((size & 0x00ff0000) >> 16);
                        buffer[5] = (byte) ((size & 0x0000ff00) >> 8);
                        buffer[6] = (byte) ((size & 0x000000ff));
                        buffer[7] = (byte) frameID;
    
                        System.arraycopy(data, 0, buffer, 8, size);
                        Log.i(TAG, "sunxiaolin,sendData,size=" + size);
                        //Log.i(TAG, "sendData,data=" + data);
                        //Log.i(TAG, "sendData,buffer=" + Utils.printHexBinary(buffer));
                        int packageNum = (size + 8) / PACKAGE_BUFFER_SIZE + 1 ;
                        Log.i(TAG, "sendDataTo,packageNum=" + packageNum);
                        try { 
                            synchronized(mLock) { 
                                InetAddress targetAddress = InetAddress.getByName(UDP_SOCKET_HOST);
                                for( int i = 0; i < packageNum; i++ ){ 
                                    if(i == packageNum - 1 ){ 
                                        mSendBuffer.dataBuf = new byte[(size + 8) - i * PACKAGE_BUFFER_SIZE];
                                        System.arraycopy(buffer, i * PACKAGE_BUFFER_SIZE, mSendBuffer.dataBuf, 0, (size + 8) - i * PACKAGE_BUFFER_SIZE);
                                    }else{ 
                                        mSendBuffer.dataBuf = new byte[PACKAGE_BUFFER_SIZE];
                                        System.arraycopy(buffer, i * PACKAGE_BUFFER_SIZE, mSendBuffer.dataBuf, 0, PACKAGE_BUFFER_SIZE);
                                    }
                                    Log.i(TAG,"sendData,write.size()=" + mSendBuffer.dataBuf.length);
                                    DatagramPacket packet = new DatagramPacket(mSendBuffer.dataBuf, mSendBuffer.dataBuf.length, targetAddress, UDP_SOCKET_PORT);
                                    mUdpSocket.send(packet);
                                }
                            }
                            Log.i(TAG, "sunxiaolin,sendData,write success.");
                        } catch (IOException e) { 
                            //e.printStackTrace();
                            Log.i(TAG, "sunxiaolin,sendData,write failed," + e.getMessage());
                        }
                    }
                });
            }
            else{ 
                Log.i(TAG,"mSocket is null");
            }
    
            return true;
        }
    
        int mTotalSize = 0;
        int mFrameSize = 0;
        byte[] mReadBuffer;
        private void readData(){ 
            new Thread(new Runnable() { 
                @Override
                public void run() { 
                    Log.i(TAG,"readDatastart");
                    while( isAndroidUdpSocketLive ){ 
                        if( mUdpSocket != null && !mUdpSocket.isClosed()) { 
                            try { 
                                mUdpSocket.receive(mRecvPacket);
                                String strReceive = new String(mRecvPacket.getData(), 0, mRecvPacket.getLength());
                                int readSize = mRecvPacket.getLength();
    
    
                                int head;
                                Log.i(TAG,"readDataread.size()=" + mRecvPacket.getLength());
                                mRecvPacket.setLength(PACKAGE_BUFFER_SIZE);
                                if( readSize > 8 ){ 
                                    head = ((mRecvPacket.getData()[0] & 0xff) << 8) | mRecvPacket.getData()[1];
    
                                    if( head == 0xA66A ){ 
                                        //Start
                                        mFrameSize = ( (mRecvPacket.getData()[3] & 0xff) << 24 | (mRecvPacket.getData()[4] & 0xff) << 16 | (mRecvPacket.getData()[5] & 0xff) << 8 | (mRecvPacket.getData()[6] & 0xff) );
                                        if(mFrameSize >= 0){ 
                                            mReadBuffer = new byte[mFrameSize + 8];
                                        }
                                        mTotalSize = 0;
                                    }
    
                                    if( mTotalSize < mFrameSize + 8 && (mTotalSize + readSize) <= mFrameSize + 8)
                                    { 
                                        System.arraycopy(mRecvPacket.getData(), 0, mReadBuffer, mTotalSize, readSize);
                                        mTotalSize += readSize;
                                        if( mTotalSize == mFrameSize + 8){ 
                                            //End
                                            byte[] imageBuffer = new byte[mFrameSize];
                                            System.arraycopy(mReadBuffer, 8, imageBuffer, 0, mFrameSize);
                                            mFrameSize = 0;
                                            Log.i(TAG,"readDatam,TotalSize=" + mTotalSize);
                                            Log.i(TAG,"readData,imageBuffer.size=" + imageBuffer.length);
                                            Message msg = new Message();
                                            msg.what = AudioFragment.UPDATE_UI;
                                            msg.obj = imageBuffer;
                                            AudioFragment.mCarHandler.sendMessage(msg);
                                        }
                                    }
                                }
                            } catch (IOException e) { 
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }).start();
        }
    }

[Android_Socket]: https://blog.csdn.net/Sunxiaolin2016/article/details/92679746